[GRASS-user] serious problem with "ROUND-OFF"

[achim]

Dear grass users,


I think I know what is needed...

to solve the problem (see below, mainly coming from splitting lines on
edges between raster-cells), I will have to:
1) identify the verts
2) move these verts on the line (direction of the line) at certain
distance (about half grid-size)

That would solve the problem mainly, but I have no idea how to deal with it.
Any help, suggestions or opinions are very welcome!

Thanks in advance,
Achim

achim schrieb:
> Hi all,
> 
> I have a problem, I really would like to solve, because many problems
> occur in my theses in further steps.
> 
> What I do is:
> 
> 1. I break lines at some lengths.
> 2. I use both vector- and raster-data for analysis, which is eg.
> updating points with raster-values or converting lines and points to raster.
> 
> The Problems are (due to rounding or "non-snapping"?):
> !Points from lines on the edge between two diagonal cells (see pictures)!
> These points do:
> 1. not belong precisely to one cell (compared with the line they come
> from (see picture v.to.rast.png)
> 2. These points sometimes don't lie on on the cells, the line is
> referred to (see picture break.png)
> 
> Any hints are very welcomed!
> 
> Thanks in advance,
> Achim
> 
> 
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> 
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